In the field of musical instrument, especially string instruments, such as guitar, one of the main considerations is how to keep maintaining the instruments in the best condition in terms of appearance as well as sound quality of the instruments. The instruments such as a classical guitar is often expensive, therefore, the great care of musical instrument is so desirable. A good musical instrument case is so important in order to protect the instrument in good condition.
A conventional musical instrument case comprises a case body for receiving a musical instrument and a cover. An outer wall of the musical instrument case is made from strong material which can be bump resistance in order to protect the musical instrument containing therein. An inner wall of the case body is lined with a soft material in order to protect the musical instrument.
The existing musical instrument case has disadvantages in which although the inner wall is lined with the soft material, there is still having a gap or space between the instrument and the inner wall. When the case is transported or carried, the instrument can unexpectedly shifted or moved during transportation and thus, it can cause damage to the instrument.
In addition, there is another disadvantage in which the conventional musical instrument cases have been designed to fit for a specific instrument model. That is, if a musician replaces the old instrument with the new one having different sizes or models, it is necessary to buy a new case to fit the new musical instrument.
European Patent Publication No. EP 1 950 734 A2 discloses a portable casing for carrying musical instrument securely. The casing interior is provided with flexible shock absorbing supports on which the non-vulnerable portions of the instrument are laid whereas the delicate and vulnerable portions are held suspended in mid-air. As soon as the casing is closed, the supports get deformed acquiring a loop-shaped structure to encircle and cradle the instrument—parts which overlie thereon and in doing so the instrument is rendered securely captive against any movement.
U.S. Pat. No. 5,833,051 discloses a multifunctional musical instrument case having a rigid case frame. The case includes a plurality of inflatable bladders for defining a compartment for receiving a guitar and for resiliently supporting the guitar placed in the compartment. The bladders when inflated or expanded substantially surround and grip the guitar in the compartment. The inflatable bladders will help securely supporting the instrument from any movement during transportation.
US Patent Publication No. US 2010/0252464 A1 discloses a soft musical instrument case having an inflatable bladder system permit protected storage and transportation of the instrument. The inflatable bladders will help securely supporting the instrument from any movement during transportation.
However, there are still the disadvantages, in which, the application of the bladder systems to help securely supporting the instrument is difficult to use. It requires a lot of the devices to inflate the bladders. The manufacturing of the conventional case is also complicated. The bladders can be exploded or having leakage during use.
In addition, most of the conventional musical instrument cases include a single wall structure. Therefore, the strength of the case may not sufficiently strong. Although it includes several layers of material, the strength still does not increase as it expected to.
There has been developed using a double-wall structure, in which usually using a foam sheet having an adhesive bonding with the outer wall or lining with foam or fabric. The disadvantage is that the case is still not sufficiently strong as it expected to be.
As described above, there is thus a need for convenient, efficient musical instrument case with a mechanism to adjust the size of the inner wall of the case to securely grip the instruments of various sizes in order for maintaining the instrument effectively.